Results 211 to 220 of about 6,063 (251)

Evidence Connecting Mercury's Magnesium Exosphere to Its Magnesium‐Rich Surface Terrane

Geophysical Research Letters, 2018
Mercury is surrounded by a tenuous, collisionless exosphere where the surface of the planet is directly exposed to the space environment. As a consequence, impacts and space weathering processes are expected to eject atoms and molecules from the surface ...
A. Merkel, R. Vervack, R. Killen, T. Cassidy, W. McClintock, L. Nittler, M. Burger   +6 more
semanticscholar   +1 more source

‘Scale Frequency’ of the Exosphere

Nature, 1962
WHISTLER measurements of nose frequency (ƒn) and time delay at this frequency (tn) give a ƒn, tn distribution well fitted by a ‘gyrofrequency’ model of electron density in the exosphere1: one for which the electron density is everywhere proportional to the magnetic field strength or gyrofrequency (ƒH).
openaire   +1 more source

Mg Exosphere of Mercury Observed by PHEBUS Onboard BepiColombo During Its Second and Third Swing‐Bys [PDF]

Journal of Geophysical Research E: Planets
International audienceMercury's exosphere is an important target for understanding the dynamics of coupled systems in space environments, tenuous planetary atmospheres, and planetary surfaces. Magnesium (Mg) is especially crucial for establishing methods
Eric Quemerais, Kazuo Yoshioka, Yudai Suzuki   +2 more
exaly   +2 more sources

Semiannual Oscillation of the Lunar Exosphere: Implications for Water and Polar Ice

Geophysical Research Letters, 2018
A time‐dependent simulation of the argon‐40 exosphere of the Moon shows that the semiannual oscillation of argon detected by the neutral mass spectrometer on the Lunar Atmosphere and Dust Environment Explorer spacecraft is consistent with adsorptive ...
R. Richard Hodges
semanticscholar   +1 more source

The calcium exosphere of Mercury

Icarus, 2005
Abstract A tenuous calcium atmosphere at Mercury, principally seen in the polar regions, was first observed in July, 1998, using the High Resolution Echelle Spectrograph (HIRES) at the W.M. Keck I telescope (Bida et al., Nature 404, 159, 2000). We report four years of observations of the calcium exosphere of Mercury, confirming the initial findings ...
R KILLEN, T BIDA, T MORGAN
openaire   +1 more source

Surface-Exosphere-Magnetosphere System Of Mercury

Space Science Reviews, 2005
Mercury is a poorly known planet, since the only space-based information comes from the three fly-bys performed in 1974 by the Mariner 10 spacecraft. Ground-based observations also provided some interesting results, but they are particularly difficult to obtain due to the planet’s proximity to the Sun.
Milillo, A., Wurz, P., Orsini, S., Delcourt, Dominique, Kallio, E., M. Killen, R., Lammer, H., Massetti, S., Mura, A., Barabash, S., Cremonese, Gabriele, A. Daglis, I., de Angelis, E., M. Di Lellis, A., Livi, S., Mangano, V., Torkar, K.   +16 more
openaire   +2 more sources

Exospheres and planetary escape

2002
A summary is given of the theory of an exosphere, the outermost region of an atmosphere where collisions can usually be neglected, and of escape of its lighter constituents. Special cases, such as energy-limited hydrodynamic loss, are briefly discussed. Surface-bounded exospheres are treated in Chapter III.3.
openaire   +1 more source

Structure of the Earth's exosphere

Journal of Geophysical Research, 1960
The main components of the earth's exosphere are neutral oxygen, neutral hydrogen atoms, ionized oxygen, and ionized hydrogen. The position of the base of the exosphere is established at an altitude of 530 km, from an analysis of density data obtained from satellite drag observations.
openaire   +1 more source

The Lunar Argon Exosphere

2020
In this chapter, we turn away from giant impacts themselves to study a particular feature hosted by the most famous outcome of a giant impact, the Moon; specifically the lunar argon exosphere with its links to the Moon’s interior. This is just one example of a connection between the consequences of giant impacts and their role in planet formation to ...
openaire   +1 more source

Atmosphere and Lowermost Exosphere

2017
The anthropogenic modifications of the atmosphere's trace gases and their heat content occurred because of world population growth, agriculture, industrial economy, deforestation, land use change, mobility, and urbanisation. CO2 concentration increased from ca.
openaire   +1 more source